This invention relates generally to arc welding, and more particularly to an improved cooling system for an arc welding torch.
Metal inert gas (MIG) arc welders feed welding filler wire from a spool through an arc welding torch to a welding zone on a workpiece. Electrical current maintains an arc between the end of the wire and the workpiece. The wire is continuously fed through a contact tip of the torch during welding and constitutes a consumable electrode which is fused into the weld puddle. The welding torch generally directs an inert gas to the welding zone which envelopes the arc. Since the contact tip of the welding torch functions as both a guide for the wire and as an electrical connector between a source of electrical energy and the wire as it slides therethrough, the contact tip is of necessity disposed relatively close to the electrical arc and therefore is subjected to the high temperature generated by the arc. In the absence of cooling, the contact tip would be subject to warping, fusion to the welding wire, oxidation, and fouling due to scale build-up.